User guide: refresh Partner Management screenshots

Fresh annotated screenshots for the partner list, groups, invite and
approve cycle, recertification, deactivation, partner users,
announcements and every Partner Profile section, with the matching
text tweaks (numbered callouts, alt text, the contacts section
description, the missing pick-up person image).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LMAt57FU2qBq45yR7YCsEZ

Author: awwaiid